CHAPTER 15 MONITORS

	Introduction :
	Video adapters are responsible for delivering the images to the monitor. They enable the monitor to display images using a variety of colors. They also give images a realistic feel and look. The monitor is like a television that displays text and graphics on the screen. The monitor is an output device that displays on the monitor screen, the information requested by the user from the system.
15.1 Video Adapters
	The video adapter is a chip installed in the system. Video adapters display both 2 Dimensional (2D) images such as textual information, and 3 Dimensional (3D) images such as those required for movies and games. The video adapter.
	Video Adapter
	The microprocessor sends the display image to the video adapter. The video adapter draws the required image and sends it to the monitor for displaying.
15.2 Components of a Video Adapter
	The video adapter is made up of the Video Basic Input Output System (BIOS), Video processor, the Video Random Access Memory (Video RAM), and the Random Access Memory Digital to Analog Converter (RAMDAC). These components work together to provide the processing needed to display complex graphics. Microprocessor Video Adapter Monitor
	15.2.1 Video BIOS
	The Video BIOS is a Read Only Memory (ROM) chip that is built on the video adapter. The Video BIOS enables communication between the system and the Video processor, as it understands the language of both the system and the Video processor. When the system wants to communicate with the video adapter, the system talks to the Video BIOS. The Video BIOS then communicates with the Video processor. Similarly, the video adapter uses the Video BIOS to communicate with the system.
	15.2.2 Video Processor
	The Video processor is like a painter, it draws the objects that must be displayed and sends them to the monitor. High-end Video processor can also process and manage the objects that must be drawn on the monitor screen.
	15.2.3 Video RAM
	The Video RAM is the memory that the video adapter uses to hold the image displayed on the monitor screen. The Video RAM is built into the video adapter card, this frees up the system memory, which would otherwise hold the image displayed on the monitor screen. However, if the video adapter is integrated in the motherboard, then the video adapter uses the system RAM.
	15.2.4 RAMDAC
	The RAMDAC converts the digital signals from the system to analog signals and sends them to the monitor.
15.3 Standards of the Video Adapters
	The video adapter standards specify the resolution that the video adapter uses to draw the display image to the monitor. The monitor must support the video adapter standard. The Video Graphics Array (VGA) standards specify that the microprocessor controls the video adapter to draw the graphic to be displayed on the monitor. The Extended Graphics Array (XGA) standards specify that the video adapter controls and draws the graphics to be displayed on the monitor. The different standards and the resolution that they support are shown in Table 15.1:
	Standard Resolution
	Video Graphics Array (VGA) 640 x 480 Super VGA (SVGA) 800 x 600 Extended Graphics Array (XGA) 1024 x 768 Super XGA (SXGA) 1280 x 1024 Ultra XGA (UXGA) 1600 x 1200
15.4 Installing the Video Adapters
	The video adapter is normally integrated in the motherboard. The video adapter is also available on a separate card that must be installed if the video adapter is not built into the motherboard, or if your video adapter does not have the capability to support graphics. You must install the video adapter card on the motherboard before installing the monitor.
	Best Practices
	1. Check the hardware for any damage after unpacking it. 2. Write the details mentioned on the label of the hardware such as the model number, and the serial number, in a safe place such as a diary. 3. Read the documentation supplied with the hardware thoroughly. 4. Check that the video adapter and the motherboard are compatible. 5. Check if there is an empty expansion slot on the motherboard to install the video adapter.
	Precautions
	1. Wear an antistatic wristband. 2. Ensure that the power supply is switched off before installing or uninstalling any hardware.
	Hands on exercise
	To install the video adapter : 1. Open the system. 2. Locate the vacant expansion slot where the video adapter must be installed. 3. Unscrew and remove the metal insert from the system case. 4. Insert the video adapter in the expansion slot using a little force and taking care not to damage the motherboard. 5. Screw the video adapter to the system case. 6. Close the system.
15.5 Types of Monitors
	Monitors can be classified on the technology that they use to display images as the Cathode Ray Tube (CRT) or the Liquid Crystal Display (LCD).
	15.5.1 Cathode Ray Tube Monitor
	The Cathode Ray Tube (CRT) monitor is an economical monitor used on most systems. The CRT monitor displays images with colors that are consistent and can be viewed comfortably from different angles. The CRT monitor is useful for displaying and working with graphics and photographs where 310 color plays an important role. CRT monitors are available with screens that are curved or flat. The CRT monitor appears.
	_ The color of the picture may differ on different monitors due to the resolution and other monitor settings. CRT monitors can be further classified on the number of colors that they use to display images such as monochrome, gray-scale, and color.
	Monochrome Monitor
	Mono means one, monochrome monitor displays the image on the screen using only one color, on a background of a contrasting color such as black or white. Monochrome monitors display images using one color such as green, orange or white. These monitors are cheaper and are used on systems that do not need to display graphics.
	Gray-Scale Monitor
	The Gray-Scale Monitor is like a black and white television. The gray-scale monitor displays the image on the screen using different shades of gray. These monitors can display both text and graphics that do not require much processing.
	Color Monitor
	The color monitor is like a color television that displays the image in a variety of colors. These monitors are useful to display colorful graphics and animations. The color monitor displays images using the three colors red, blue, and green. It mixes these three colors in different combinations to display a variety of colors.
	Color Monitor15.5.2 Liquid Crystal Display (LCD) Monitors
	The LCD monitors are thin and they use little space. They are light in weight, consume less energy, and are used on laptops. The picture on the LCD monitor does not flicker and thus reduces eyestrain, because the whole image is drawn at once on the LCD screen. The LCD monitor is also available for desktop use
15.6 Features of the Monitor
	The features of the monitor specify the additional qualities of the monitor. The better the features of the monitor, the more the monitor costs. These features provide a better view of the display picture on the monitor.
	15.6.1 Size
	The size of the monitor specifies the length of the monitor in inches. Monitors are available in the sizes ranging from 14 inches to 22 inches. The size of the monitor is measured diagonally.
	Measuring the Monitor Size
	The sides of the monitor screen do not display any content, as they are covered by plastic. The part that actually displays the content is known as the viewable image size. The orientation of the monitor specifies the method the monitor uses to present the display image on the screen. The monitor can have the portrait orientation with its height greater than the width.
	Portrait Monitor
	15.6.2 Resolution
	Newspapers have pictures displayed in them. If you have a closer look at the picture, you will find that the picture consists of tiny dots. The monitor screen also displays the text and graphics like the newspaper using tiny dots know as pixels.
	Pixels in an Image
	The more the dots, the higher the resolution, the more sharp and clear the display image on the screen. The resolution of the monitor is measured using two numbers. The first number specifies the number of dots displayed on a single line of the screen. The second number specifies the number of lines on the screen. For example of the resolution is specified as 640 x 480, this means that the monitor can display 640 dots on one line and can also display 480 lines on the screen. Monitors set to high-resolution display more information on the screen by decreasing the size of the images. A low-resolution monitor shows less information on the screen by increasing the size of the image. Pixel
	15.6.3 Antiglare Screen
	The monitor screen gives out bright light, and also acts like a mirror that reflects light. You can see on the screen the reflection the light from tube lights and bulbs this puts a strain on your eyes. Antiglare screens reduce the glare and eye strain. Some monitors screen have a built-in antiglare screen, you can also use an external antiglare to reduce eyestrain.
	15.7 Monitor Settings
	The monitor has settings that enable you to adjust the display settings of the monitor. Using these settings, you can set the display screen size, the brightness and the contrast. These settings are available as separate buttons or wheels on the front panel of the monitor or using a button that displays the settings menu. The availability of these settings and the method to access them differs from one monitor model to another.
	15.7.1 Brightness
	The change in the amount of the light changes the brightness of objects. In the same way, the brightness setting enables you to brighten up the display picture on the screen when it appears dark. It also enables you to darken the display picture on the screen if it is too bright. The icon representing this setting appears like a sun.
	15.7.2 Contrast
	The contrast specifies the difference between the lighter and the darker colors in the display picture, such as the colors black and white. The higher the contrast the more the difference between the two contrasting colors. If the contrast is low then the two contrasting colors appear similar. The contrast setting enables you to increase and decrease the contrast level.
	15.7.3 Horizontal Size
	This setting allows you to increase and decrease the size of the display image horizontally on the screen. You can stretch the image to span the entire monitor screen horizontally. Setting the horizontal size to the maximum may not allow you to view the display picture at the sides of the screen, as it may not be displayed on the viewable area of the screen.
	15.7.4 Vertical Size
	This setting allows you to increase and decrease the size of the display image vertically on the screen. You can stretch the image to span the entire monitor screen vertically. Setting the vertical size to the maximum may not allow you to view the display picture at the top and bottom of the screen, as it may not be displayed on the viewable area of the screen.
	15.7.5 Horizontal Position
	You can decrease the horizontal size of the display picture. When the size of the display picture is less than that of the viewable area, the screen between the display picture and the monitor screen will be displayed in the black color. The horizontal position setting enables you to move the display picture to the right and left direction on the screen. This enables you to adjust the display picture to display it in the center of the screen.
	15.7.6 Vertical Position
	You can decrease the vertical size of the display picture. When the size of the display picture is less than that of the viewable area, the screen between the display picture and the monitor screen will be displayed in the black color. The vertical position setting enables you to move the display picture up and down on the screen. This enables you to adjust the display picture to display it in the center of the screen.
	15.7.7 Degauss
	The magnetic field of the earth or the magnetic field emitted from objects placed close to the monitor that have magnets in them such as speakers, can magnetize the monitor. As a result, the display picture on the monitor will not be displayed properly and the display picture at the edges of the monitor may be displayed in red, blue or green color. Degaussing the monitor removes the magnetism from the monitor and restores the display picture. Some monitors automatically degauss the monitor when it is switched on. The icons representing this appear.
	15.7.8 Language
	Monitors that enable you to modify the settings using a menu display the setting name and description on the screen. You can modify the menu language to suit the local language or the one that you are comfortable with.
	15.7.9 Corner/Trapezoid Correction
	If you look at an object through a round transparent drinking glass, the object appears distorted. Similarly, the CRT monitor may also have a convex screen that may display a distorted image. The corner / trapezoid correction setting enables you to adjust the display image to correct this distortion in the display image.
	15.8 Installing the Monitor
	The monitor must be installed by attaching the signal cable to the system and the power cord to the power outlet. Monitors also have a special stand that enables you to easily turn the monitor for comfortable viewing of the display screen.
	Best Practice
	1. Follow steps 1 to 3 from best practice for installing the video adapter. 2. Check the back of the system case to check if the power cord from the monitor can be connected to the system power supply.
	Precaution
	Ensure that the power supply is switched off before installing or uninstalling any hardware.
	Hands on exercise
	To install the monitor stand : 1. Turn the monitor upside-down. Connect to the monitor Connect to the system
	Upside-down Monitor
	2. Place the stand over the base of the monitor. 3. Slide the base to lock it to the monitor.
	Locking the Base to the Monitor
	4. Turn the monitor right side up.
	To install the monitor :
	1. Connect one end of the power cord to the power port at the back of the monitor. 2. Connect the other end of the power cord to the power outlet or to the system power supply case. 3. Check the monitor using the built-in Power On Self Test (POST). 4. Connect one end of the signal cable to the video port at the back of the monitor, if it is not already connected to the monitor. 5. Connect the other end of the signal cable to the back of the system case, to the video adapter. 6. Turn the hand screws of the signal cable to lock the signal cable to the system case.
	15.9 Testing the Monitor
	Most monitors have a built-in POST. This enables you to check that the monitor is working properly and to check if the monitor is receiving input from the system. You must use the POST to check that the monitor is working properly, especially when you get a new monitor for the system. The POST also displays a message such as Sync Out of Range if the monitor cannot handle the resolution or frequency sent by the video adapter. It also appears if the signal cable is damaged.
	Hands on exercise
	To use the POST to check if the monitor is working : 1. Check that the monitor power cord is connected to the power supply. 2. Check if the signal cable is connected to the system. If connected, disconnect it. 3. Switch the power supply on. 4. Switch the monitor on. A message will appear on the display screen to show that the monitor is working but not receiving signals from the system. 5. Switch the monitor and the power supply off. 6. Reconnect the signal cable to the system.
15.10 Troubleshooting the Video Adapter
	The problems with the video adapter prevent displaying images on the monitor screen. The video adapter may also give problems if it conflicts with the other hardware installed. _ It is preferred to troubleshoot the monitor before troubleshooting the video adapter. 1. Check that the video adapter is not damaged if it is a new one. 2. Check if the video adapter is compatible with the motherboard. 3. Open the system and push the video adapter firmly into the expansion slot if it is loose. 4. Remove the video adapter from the current expansion slot and install it in another free expansion slot.
15.11 Troubleshooting the Monitor
	Troubleshooting the monitor solves the problems associated with the monitor. The monitor has a Light Emitting Diode (LED) that glows continuously when the system is on. The LED blinks when the system is in the stand by mode or is shut down. Problems in displaying the picture on a new monitor may be caused if the monitor is defective. The CRT monitor uses a very high voltage to produce the display image on the monitor screen. You must not open the case of the monitor under any circumstances as it can cause harm or even death.
	15.11.1 The Display Picture Appears Too Bright or Dark
	The display picture appears too bright or too dark when there is a problem with the brightness or contrast. 1. Adjust the brightness settings using the control on the front panel. 2. Adjust the contrast settings using the control on the front panel. 319 3. Switch the lights off to check that the brightness problem is not caused due to the lighting in the room. 4. Try using an antiglare screen.
	15.11.2 There is No Display Picture On the Screen
	The display picture does not appear on the screen if the monitor is not receiving signals from the system. 1. Press a button on the keyboard or move the mouse to wake the system if it is in the standby mode. 2. Switch the monitor off and then switch it back on. 3. Increase the brightness and the contrast. 4. Press the power supply cable and the signal cable firmly in the sockets. 5. Reboot the system. 6. Use the POST of the monitor to check that the monitor is working. 7. Troubleshoot the video adapter.
	15.11.3 Cannot Change the Settings )
	The monitor setting specifies the way that the picture is displayed on the monitor screen. These settings can be changed using buttons from the front panel of the monitor. 1. Check if the settings are locked. Refer to the user manual to unlock the settings. 2. Check if the settings are set at the maximum or minimum limit.
	15.11.4 The Display Picture Appears Wavy
	The display picture appears wavy when there is some strong electrical or magnetic field disrupting the monitor. 1. Relocate devices that emit strong magnetic fields such as speakers, and mobile phones that are kept near the monitor. 2. Connect the monitor to different power supply socket. 3. Change the location of the monitor.